Bath Electrical Heating Device for Deactivation

ABSTRACT

A bath electrical heating device for deactivation designed to provide heating of bath deactivation and the deactivating solution in it before deactivation of reactor facility equipment and ensuring the removal of excess heat in the process of deactivation. The invention improves reliability, reduces the material consumption of the device and simplifies the structure installation and repair. The device performs at least from three heat insulation blocks in the form of coaxial metal screens, installed with an air gap from the heater. The heater with current leads is made in hermetic perform, each heat insulation blocks supplemented with an air-gap coaxial metal protective casing. The air gap of which in the upper part is covered with a cap with a visor whose diameter exceeds the external diameter of the protective casing, wherein solid cover of the upper protective casing install a sealed coupling.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a US 371 Application from PCT/RU2017/000797 filedOct. 27, 2017, which claims priority to Russia Application 2016142508filed Oct. 28, 2016, the technical disclosures of which are herebyincorporated herein by reference.

The device relates to nuclear power, in particular to the electricalequipment of a reactor facility with a Water-Water Energetic Reactor (RFwith WWER). In general, the bath electrical heating device fordeactivation designed to provide heating of bath deactivation and thedeactivating solution in it before deactivation of RF equipment andensuring the removal of excess heat in the process of deactivation of RFequipment.

The known technical solution (RF Patent No. 2219425, IPC F 16 L 59/06,priority Sep. 20, 2002) applies pipeline shields attenuating the heattransferring radiation.

The drawbacks of such structure are as follows:

complexity of arranging a large number of enclosed air cavities;

absence of electric heating elements;

complexity of structure installation and repair;

impossibility to withdraw excessive heat.

The closest to the technical essence is the device (Patent “PipelineHeater”, utility model 38214 U1 F16L53/00, application: 2003128914/20,Sep. 29, 2003, published on May 27, 2004), which contains placed on theouter surface of the pipeline, blocks in the form of sections filledwith heat-insulating material, on the inner wall of which there is anelectric heating element with current leads, wherein the electricalheating element is made of a wire of high specific electric resistance,provided with insulating elements.

The drawbacks of the known structure, taken as prototype, are asfollows:

large material consumption for the structure;

danger of short-circuiting of heater to the ground in case of spillageof deactivating solution; complexity (impossibility) of deactivation ofheat insulation in case of spillage of deactivating solution;

impossibility to withdraw excessive heat.

These drawbacks are due to the fact that hygroscopic materials are usedas heat insulation,

ceramic insulators are used as electrical insulation of the heater, andin addition, the construction does not ensure the removal of excess heatin the process of decontamination of RF equipment.

The said drawbacks are eliminated by the claimed structure.

The object of the invention is to provide a creation of bath electricalheating device for deactivation of RF equipment, technologicalparameters and safety of maintenance personnel in the process ofdeactivation of RF equipment.

The technical effect of this invention is to improve reliability, reducethe material consumption of the device and simplification of structureinstallation and repair. Another technical result is to ensure that thedevice can be deactivated.

The technical result is achieved by the fact that in the bath electricalheating device for deactivation of vertical execution, that contained aheater located on the outer surface of the pipeline from a wire withhigh electric resistance with current leads and couplings and heatinsulation in the form of blocks, the device is proposed to perform atleast from three heat insulation blocks in the form of coaxial metalscreens, installed with an air gap from the heater, the heater withcurrent leads must be made in hermetic perform, each heat insulationblocks supplemented with an air-gap coaxial metal protective casing, theair gap of which in the upper part is covered with a cap with a visorwhose diameter exceeds the external diameter of the protective casing,wherein solid cover of the upper protective casing install a sealedcoupling, in addition, in the upper and lower part of the side surfaceof the protective casing make through holes, the total area of whichshould be equal to or more than the area of the air gap between theouter screen and protective casing.

The concept of the invention is explained by the drawing. FIG. 1 showsthe general view of the bath for deactivation 1 of vertical execution.Hermetic heater 2, for example, from the heat-resistant cable KHMCHX-Haccording to TU16.K03-43-2006, is mounted on the bath for deactivation1. Heat insulation of the heater 2 is made in the form of blocks 3 ofcoaxial metal screens 4, for example, from thin sheetcorrosion-resistant steel 08X18H10T according to GOST 5582-75, which areinstalled with an air gap 5. Hermetic current leads 6 are installed onthe outer surface of the screen 4. Each heat insulation unit 3 isequipped with installed with an air gap 7 coaxial metallic protectivecasing 8, an air gap 7 of the protective cover 8 in the upper part isclosed with a visor 9, whose diameter is larger than the outer diameterof the protective casing 8, wherein in the solid cover 10 upperprotective casing 8 a sealed coupling 11 is installed. In addition, atthe top and bottom of the side surface of the protective casing 8 aremade through holes 12, total area of which is not less than the area ofthe air gap between the outer screen 4 and the protective casing 8.

The installation of the device begins with the installation of theheater 2, then the internal screens 4 heat insulation blocks 3, performelectrical installation and install an external protective casing 8. Inpreparation for operation heater 2 and heat insulation blocks 3 providethe initial heating of deactivating solution and bath for deactivation1. By choosing he number of screens 4 and size of air gap 5 requiredsurface temperature of heat insulation block 3 is reached. Perform theheater 2, current lead 6 and the coupling 11 in hermetic executioneliminates the possibility of a short circuit with possible leaks of thedeactivating solution. Since the outer diameter of visor 9 exceeds theouter diameter of the protective casing 8, it is also excluded that thedeactivation solution can enter the interior of the device. In theprocess of deactivation RF equipment excess heat is removed from thebath for deactivation 1 through the openings 12 due to air circulationbetween the heat insulation unit 3 and protective casing 8. By selectingsize of air gap 7 temperature reduction of protective casing 8 isachieved to ensure the safety of maintenance personnel in the process ofdeactivation of RF equipment. All materials used in the device allowdeactivation in case of spillage of deactivating solution.

Thus, use of the claimed technical solution in comparison with knowndevices provides increased reliability of the device: reduced materialconsumption, simplified installation and repair of the device, provided,if necessary, the possibility of device deactivation, initial heating ofthe equipment is provided by the attenuation of radiant heat exchange bythe screens, provided in deactivation process removal of excess heat dueto circulation of air between the heat insulation block and protectivecasing.

1. A bath electrical heating device for deactivation of verticalexecution, that contained a heater located on the outer surface of bathdeactivation from a wire with high electric resistance with currentleads and couplings and thermal insulation blocks, wherein the deviceconsists at least from three heat insulation blocks in the form ofcoaxial metal screens and installed with an air gap from the heater,wherein the heater with current leads is made in hermetic perform, eachheat insulation blocks supplemented with an coaxial metal protectivecasing, the air gap between the heat insulation blocks and protectivecasing in upper part is covered with a cap with a visor whose diameterexceeds the external diameter of the protective casing, wherein solidcover of the upper protective casing install a sealed coupling, inaddition, in the upper and lower part of the side surface of theprotective casing make through holes, the total area of which is equalto or greater than the area of the air gap between the heat insulationblock and protective casing.